posted on Nov, 21 2015 @ 03:45 PM
Spacesuits are made with many layers. The most important layer is the rubber "pressure Bladder" that holds the air in. On its own, it would balloon
in the vacuum of space. Fortunately, engineers are smart, and realized this. That's why the outside of the pressure bladder is covered with a
"restraint layer" to keep it from ballooning. On the Gemini and Apollo suits, the restraint layer was a nylon mesh. On the Shuttle & ISS suits , the
restraint layer is a Dacron fabric.
Outside the pressure bladder and restraint layer are several layers of insulation. The outermost layer is a very tough covering that protects against
punctures and abrasions.
Inside the pressure bladder, the astronaut has comfort layers to prevent chafing against the rubber and a liquid cooling garment, which was basically
like long underwear with a network of tubes through which they run water to cool the astronaut.
Trivia 1: The first EVA suit, worn by Alexei Leonov, did not have a liquid cooling garment or a restraint layer. It ballooned badly:
"My suit was becoming deformed, my hands had slipped out of the gloves, my feet came out of the boots. The suit felt loose around my body. I had to
"I couldn’t pull myself back using the cord. And what’s more with this misshapen suit it would be impossible to fit through the airlock."
Without telling ground control, the cosmonaut decided to bleed half of the air out of his spacesuit through a valve in its lining. This risked
starving his body of oxygen, but if he couldn't get back inside the capsule, he’d be dead anyway. Leonov let out a little oxygen at a time to
reduce the pressure. But as he did so, he started to feel the first hints of decompression sickness.
"I began to get pins and needles in my legs and hands. I was entering the danger zone, I knew this could be fatal.”
He started coiling the cord in order to haul himself back. When he finally reached the airlock, he pushed the camera in, grabbed the sides and lurched
through head first.
The extreme physical exertion had caused his temperature to soar; he was now at risk of heatstroke and sweating uncontrollably. The globules filled
his helmet, obscuring his vision.
Leonov was supposed to re-enter the airlock feet first. Getting in the wrong way meant he had to turn himself around in the cramped space to make
sure the umbilical cord was inside and the hatch was locked.
He says: “It was the most difficult thing: I’m in this suit and I had to turn around in the airlock. But with the perspiration, I couldn’t see
anything. I don’t normally sweat much, but on that day I lost 6kg in weight.”
After curling around in his bulky suit, in such a narrow space, Leonov finally made it back inside the craft.
Trivia 2: The American Gemini suits had the restraint layer, but not the liquid cooling garments. Combined with inadequate training (they hadn't
learned to train in a simulated zero-G water tank yet), hand-holds and foot restraints, the astronauts on Gemini 9, 10 & 11 all over-exerted and
Trivia 3: On Peter Jackson's "Hobbit" movies, the actors playing the dwarves had on layers of hair, armor, costumes and padded "fat suits". To keep
them from falling-over from heat stroke, underneath it all they wore the same kind of liquid cooling garments that the astronauts use.
Hope this helps.